The present invention relates generally to systems for cutting pattern pieces from textiles or similar flexible sheet material, and deals more particularly with an apparatus and method for separating cut pattern pieces from adjacent waste material following the cutting operation.
The invention is particularly well adapted for use in a fully automated cutting system including at least one conveyor table for supporting sheet material and for feeding it to and from a cutting station, and it is therefore herein illustrated and described in association with such a system. The invention is not, however, necessarily limited to such a system and may also be used beneficially with non-automated or semi-automated systems an with systems using one or more non-conveyor tables with fixed material supporting surfaces, the material being slid over such supporting surfaces in being moved from one work station to another.
Conveyor cutting tables are known for use in feeding sheet material to and from a cutting station associated with the table. In some applications a single layer of sheet material may be supported and fed by the table, and in other applications the table may be used to feed and support a layup of material formed by spreading multiple layers of sheet material on top of one another prior to the cutting operation. The cutting of a layup rather than a single layer has the advantage that a single traversal by the cutting tool of a cutting path having a shape corresponding to the periphery of a pattern piece cuts from the layup an entire stack of such pattern pieces. The pattern pieces to be cut from either a single layer or a layup of material are generally initially laid out in a cutting pattern, referred to as a "marker", to provide an optimal arrangement of the pattern pieces maximizing usage of the material and leaving as little waste material as possible.
The entire process of cutting sheet material, either in single layers or in layups, involves basically the three steps of spreading the sheet material, cutting the spread material, and separating the cut pieces from the waste material. When cutting a single layer of sheet material, or a layup containing only a few layers, the material is sometimes fed from one or a small number of fixed supply rolls directly to the cutting station, so that the spreading occurs at or near the cutting station. More usually however, especially in the case of cutting high layups, the material is spread over a relatively long spreading surface in advance of being moved to the cutting station. This spreading surface may be formed by an advance portion of the same conveyor table as provides the cutting station, or in other cases may be provided by a separate non-conveyor or conveyor table from which the spread material is moved to the cutting table at the proper time.
The step of separating the cut pieces from the waste material may be accomplished by stopping the cutting process, after a given longitudinal portion of the material is cut at the cutting station, and then removing the cut pieces by picking them up by hand from the cutting station before a fresh uncut portion of material is moved to the cutting station for subsequent cutting. To improve the efficiency of the cutting station, it is also known to move the cut portion of sheet material to a separate take-off station where the process of separating the cut pieces from the waste material can take place while the cutting station operates on a fresh portion of material. In some instances the take-off station may be provided by a portion of the same conveyor table as provides the cutting station, and in other instances the take-off station may constitute a separate table to which the cut portion of material is moved following its cutting at the cutting station.
It is also known from U.S. Pat. No. 3,765,349, when cutting layups of sheet material, to bundle the cut stacks of pattern pieces by inserting stitches or fasteners into the stacks, so that the bundled stacks can then be more readily removed from the waste material at the take-off station, and so that the stacks will remain intact until reaching a subsequent sewing or other work station. This bundling may occur at the cutting station, at the take-off station or at some other station.
In any event, the removal of the cut pieces from the waste material, whether dealing with single pieces cut from a single layer or with stacks of pieces cut from a layup, is a relatively time-consuming operation since it requires one or more persons to locate, grasp, lift and transfer to a suitable receptacle or delivery station each pattern piece or stack of pattern pieces. Some attempts have been made or contemplated in the past to automate this operation through the use of robots simulating the work of human operators, but this in turn requires relatively costly and complex equipment and associated control systems.
The general object of this invention is therefore to provide a simple apparatus and method for use in a sheet material cutting system for separating cut pattern pieces from waste material after the sheet material is cut at a cutting station, the apparatus and method eliminating the need for human operators or robot type separating equipment.
Other objects and advantages of the invention will be apparent from the following detailed description of a preferred embodiment and from the accompanying drawings and claims.